A major priority for the addiction treatment field is the development of medications for the treatment of cocaine abuse and dependence. An obstacle to the development of such medications is the lengthy duration necessary to conduct clinical trials. This project proposes a methodology which can rapidly and efficiently screen medications for their benefits as pharmacotherapies for cocaine treatment. The study will make use of two research sites which have a successful history of recruiting large numbers of subjects into addiction pharmacotherapy trials. The Matrix Center West Los Angeles Clinic will provide 350 primary cocaine abusers for the study of five potentially beneficial medications. The Pizarro Treatment Center will provide 280 primary opiate addicts maintained on opiate maintenance pharmacotherapy who have a diagnosis of cocaine abuse or dependence. Four medications will be studied at this site. Each medication will be assessed under double-blind conditions, using a standardized psychosocial protocol, with standardized induction measures. Each medication will be evaluated over a 16 week period with 70 subjects per study (35 medication, 35 placebo). Through the use of this rapid screening methodology, the efficiency of identifying useful medications for cocaine abuse treatment will be significantly improved.